TriMet will close or partially close six park-and-ride lots in Tigard, Tualatin and Southwest Portland to conduct pavement maintenance and re-striping over the next month.

"Crews will be sealing the pavement and restriping the park and rides," said Roberta Altstadt, a TriMet spokeswoman. "Similar work was completed at parking lots on the east side last summer."

Half of the spaces at five lots will be closed for the work at any given time during the work. Riders should expect the open sections to fill up early and make a Plan B.

Here's the schedule of park-and-ride closures:

Sunday, July 20: Both of the bottom and upper decks of the Tigard Transit Center will be closed. Alternatives: Use the Tigard Park & Ride at Southwest 74th Avenue and Pacific Highway (220 spaces), which is served by the Line 12 on weekends; or the Barbur Boulevard Park & Ride (368 spaces) at 9712 SW Barbur Blvd. in Portland, which is also served by the Line 12 on weekends.

Saturday, July 26, and Sunday, July 27: Barbur Boulevard. Half of the spaces will be closed each day. Use the Tigard Park & Ride at Southwest 74th Avenue and Pacific Highway (220 spaces), which is served by the Line 12 on weekends; or the Tigard Transit Center (103 spaces) at 8960 SW Commercial in Tigard, which is served by the lines 12 and 45 as alternatives.

Tuesday, July 29 through Wednesday, July 30: Mohawk Park & Ride in Tualatin. Half of the spaces will be closed each day. Alternatives: Tualatin Park & Ride (466 spaces), located at Southwest 72nd Avenue and Bridgeport Road (220 spaces), which is served by the lines 76 and 96; or the Tualatin South Park & Ride (147 spaces), located at 18955 SW Boones Ferry Rd., which is served by the Line 76.

Tuesday, Aug. 5 through Wednesday, Aug. 6: Progress Park & Ride in Tigard. Half of the spaces will be closed each day. Alternatives: Since there is no other park and ride along the Line 92 route, plan an alternate trip using Trip Planner at ride.trimet.org.

Tuesday, Aug. 12 through Wednesday, Aug. 13: Tualatin Park & Ride. Half of the spaces will be closed each day. Alternatives: Use the Mohawk Park & Ride, which is served by the lines 76 and 96, or plan an alternate trip with Trip Planner map at ride.trimet.org.